Optical access network having emitter-free customer premise equipment and adaptive communication scheduling

A network system comprising:

• an access device comprising an optical interface module that outputs a plurality of pairs of optical communication signals, each of the pairs of optical communication signals comprising a modulated optical transmit signal and an unmodulated optical receive signal, each of the pairs of optical communication signals having a different wavelength;
• a plurality of customer premise equipment (CPEs), each of the CPEs comprising an optical interface module to receive the modulated optical transmit signal and the unmodulated optical receive signal for any of the plurality of pairs of optical communication signals, wherein the optical interface module includes a receive module to demodulate the modulated optical transmit signal into inbound symbols and a transmit module having an optical modulator and reflective optics to modulate the unmodulated optical receive signal in accordance with a data signal and reflect a modulated optical receive signal to communicate outbound data symbols to the access device;
• a comb filter coupled between the access device and the plurality of CPEs that wave division multiplexes each of the pairs of optical communication signals from a common optical fiber to a plurality of N ports, each of the N ports communicating a different one of the pairs of optical communication signals at a different one of the wavelengths;
• and
• a respective optical splitter coupled to each of the N ports of the comb filter, each of the optical splitters configured to split the modulated optical transmit signal and the unmodulated optical receive signal for the respective port of the comb filer into a plurality of M sets of the optical transmit signals and the unmodulated optical receive signals, each of the optical transmit signals and the unmodulated optical receive signals of the same set having the same wavelength,
• wherein each of the CPEs is coupled to a different port of the optical splitters.

A network system comprising:

• an access device comprising an optical interface module that outputs a plurality of pairs of optical communication signals, each of the pairs of optical communication signals comprising a modulated optical transmit signal and an unmodulated optical receive signal, each of the pairs of optical communication signals having a different wavelength;
• and
• a plurality of customer premise equipment (CPEs), each of the CPEs comprising an optical interface module to receive the modulated optical transmit signal and the unmodulated optical receive signal for any of the plurality of pairs of optical communication signals, wherein the optical interface module includes a receive module to demodulate the modulated optical transmit signal into inbound symbols and a transmit module having an optical modulator and reflective optics to modulate the unmodulated optical receive signal in accordance with a data signal and reflect a modulated optical receive signal to communicate outbound data symbols to the access device,
• wherein the access device comprises a first component of a distributed phase lock loop that locks onto a transmit clock of the optical receive signal reflected back from a first one of the CPEs and output a delay adjustment based on a comparison of the transmit clock of the first one of the CPEUs and a master clock, and
• wherein the first one of the CPEs comprises a second component of the distributed phase lock loop that adjusts the transmit clock based on the delay adjustment received from the access device.

A method comprising:

• executing a plurality of schedulers on an access device to schedule output, with an optical interface module of the access device, a plurality of pairs of optical communication signals, each of the pairs of optical communication signals comprising a modulated optical transmit signal and an unmodulated optical receive signal, each of the pairs of optical communication signals having a different wavelength, wherein each of the schedulers corresponds to a different set of one or more customer premise equipment (CPEs) receiving a respective one of the pairs of optical communication signals;
• receiving, with an optical interface of a first one of the CPEs, the modulated optical transmit signal and the unmodulated optical receive signal of one of the plurality of pairs of optical communication signals;
• demodulating, with the optical interface of the first one of the CPEs, the modulated optical transmit signal into inbound symbols;
• modulating, with the optical interface of the first one of the CPEs, the unmodulated optical receive signal in accordance with a data signal to produce a modulated optical receive signal of outbound data symbols;
• and
• reflecting, with the optical interface of the first one of the CPEs, the modulated optical receive signal back to the access device to communicate the outbound data symbols to the access device.

An access device comprising:

• a plurality of interfaces;
• a switch fabric to forward network packets between the plurality of interfaces;
• and
• a plurality of schedulers executed by the access device,
• wherein at least one of the interfaces comprises an optical interface module that outputs a plurality of pairs of optical communication signals,
• wherein each of the pairs of optical communication signals comprises a modulated optical transmit signal to transmit outbound symbols to a respective set of one or more customer premise equipment (CPEs) and an unmodulated optical receive signal to receive inbound symbols from the respective set of CPEs, and
• wherein each of the schedulers corresponds to a different one of the sets of CPEs and schedules, for a respective one of the pairs of optical communication signals, downstream communication to the set of CPEs by the modulated optical transmit signals and upstream communication from the CPEs by the respective unmodulated optical receive signal.